Effects of Cr contents in Fe-based bulk metallic glasses on the glass forming ability and the corrosion resistance

Fe-based bulk metallic glasses of Fe_69.9-xC_7.1Si_3.3B_5.5P_8.7Cr_xMo_2.5Al_2.0Co_1.0 (x = 0.0, 2.3-12.3) with high glass forming ability and good corrosion resistance were fabricated using industrial raw materials. Glass forming ability of the Fe-based bulk metallic glasses tends to decrease with the Cr content, while the corrosion resistance increases with the Cr content. A homogeneous passive layer on the amorphous sample with 12.3 at% Cr can be formed leading to superior corrosion resistance of the amorphous sample to an austenitic stainless steel (SUS304) in the 0.5 M H₂SO₄ and 1N HCl solutions at 298 K. Fe-based bulk metallic glasses with an optimum combination of glass forming ability and corrosion resistance can be produced in large quantities through a systematic control of the Cr content for extensive practical applications.